Abstract of the Study ?Community psychosis risk screening: An instrument development study? The ongoing, funded parent study aims to develop a brief, valid screening questionnaire to identify individuals at risk for psychosis in non-clinical populations across 3 large, community catchment areas with diverse populations. This is a needed study, as the current screening tools for at-risk psychotic populations have been validated only in clinical and/or treatment seeking samples, which are not likely to generalize beyond these specialized settings. This project is administering 3 well-known psychosis risk screeners, as well as symptom- based (e.g., depression, anxiety, etc.) and risk-factor based questionnaires (e.g., cannabis and other substance use, a family history of major mental disorders, trauma history) to 12,000 adolescents/young adults in local communities across 3 demographically diverse sites (the greater Philadelphia, Baltimore, and Chicago areas, including neighboring rural/suburban areas). Based on established cut-off scores from the 3 psychosis screeners, 2,000 subjects deemed as questionnaire higher risk (QHR; n=1,000) and questionnaire lower risk (QLR; n=1,000) for psychosis (estimated sample sizes based on pilot data and anticipated loss to follow up) will be invited to complete semi-structured interviews to determine clinical high risk (CHR) for psychosis status based on the Structured Interview for Psychosis-Risk Syndromes (SIPS) and to assess current/past major mental disorders based on the Structured Clinical Interview for DSM-5 (SCID-5). The SIPS psychosis-risk persistence syndromes and the DSM-5 attenuated positive syndrome (both assessed with the SIPS 5.6) also will be collected and will be examined in supplementary analyses. Based on preliminary data and conservative estimates, we anticipate that 186 of the QHR group will be considered CHR for psychosis. The specific aims are as follows: 1) to determine norms and prevalence rates of attenuated positive psychotic symptoms across 3 diverse, community catchment areas and 2) to develop a screening questionnaire, inclusive of both symptom-based and risk factor-based questions, that is validated against the SIPS to identify those at CHR for psychosis in the community. This is the first study in the U.S. to determine the rate of subthreshold psychotic symptoms across diverse non-help seeking samples, which is essential for any investigation that uses dimensional approaches to psychotic disorders. Further, this study will develop an essential screening tool that will identify which individuals have the greatest need of follow-up with structured interviews in CHR studies or clinical settings to determine psychosis-risk status. This tool is will be valuable given findings that those who develop psychotic disorders often do not seek treatment until after the onset of the disorder, and that duration of untreated psychosis is associated with more serious clinical outcomes. The funded study has the potential for major contributions to the early detection and prevention of psychotic disorders.The proposed diversity supplement will fit within this award by providing essential training and time for a predoctoral student, Arielle Ered, to develop her program of investigating neural and psychosocial risk factors for psychosis.